wondering why when I start driving my power locks do not lock automatically? on 2000 Chevrolet Blazer

I noticed that when I started driving my doors would automatically lock when I put the gear into drive and starting driving. But now I noticed lately when I put it into drive and start driving it does not lock automatically anymore and I am wondering why this is?

I would have to see if I can find the info. My 1500HD has instructions in it. If I remember you use the door lock button in a certain sequence to set for the operation you want to work. By the way if I remember correctly, the newer ones will lock after you start driving and reach a speed of about 10mph before the locks engage.

OK your blazer does not have a reset. It controlled by the BCM, and the lock out feature is supposed to work through it. 1 test says to install the key into the lock cylinder, do not turn the key, leave it at off position and see if the chime works with the door open. Check this first.

Ok, reason i ask is my 2000 Blazer 'LT' does not, never has but yours may be different somehow! Frankly I like it that way, if I want my doors locked, I will lock them!! Just push a button!!! Keyless entry still work ok?